Process for the improvement of textiles by the use of silicones and hardening accelerators

ABSTRACT

Process for the improvement of fibrous materials, particularly in the finishing of textiles, by the use of silicones and hardening accelerators, which comprises treating the materials with aqueous emulsions of silicones and using as hardening accelerators an addition compound of aminoalkyltrifluorosilane and hydrofluoric acid. The fibrous materials thus treated exhibit an excellent and lasting water repellence and a high resistance to rubbing off of colors.

United States Patent [72] Inventors Horst Kroning Dresden;

Christian Dathe, Radebeul; Richard Muller, Radebeul, all of Germany797,682

Feb. 7, 1969 Nov. 9, 1971 Institut fur Silikon-und Fluorkarbon- ChemieRadebeul, Germany [2]] Appl. No. [22] Filed [45] Patented [73] Assignee[54] PROCESS FOR THE IMPROVEMENT 0F TEXTILES BY THE USE OF SILICONES ANDHARDENING ACCELERATORS 7 Claims, No Drawings D06ml5/66 1 17/161, 140,139.4, 139.5; 260/29.2, 29.4, 46.5

[56] References Cited UNITED STATES PATENTS 2,689,860 9/1954 Rust117/139.5 X 2,728,692 12/1955 Dennett 117/161 X 2,757,152 7/1956 Solomon260/29.4 X 2,774,690 12/1956 Cockett et a1. 117/161 X 2,789,956 4/1957Eder ll7/l6l X 2,914,836 12/1959 Montgomery 117/161 X 3,458,555 7/1969Dathe 260/448.2

Primary E.raminerWilliam D. Martin Assistant E.raminerMathew R. P.Perrone, Jr. A!l0rne vTab T. Thein thus treated exhibit an excellent andlasting water repellence and a high resistance to rubbing offofcolors.

PROCESS FOR THE IMPROVEMENT OF TEXTILES BY THE USE OF SILICONES ANDHARDENING ACCELERATORS The present invention relates to a process forthe improvement of fibrous materials, for instance, for finishingtextiles by means of silicones.

it is known that for finishing textiles, solutions or aqueous emulsionsof dialkylpyolysiloxanes and/or of alkylhydrogenpolysiloxanes can beused, both called silicones hereinafter. In order to make the siliconesadhere to the materials to be finished, at reduced hardeningtemperatures, it is necessary to use simultaneously some condensationaccelerators or catalysts. It has already been suggested to use ascatalysts organometallic compounds, e.g. tin, zinc or lead salts ofcarboxylic acids, and also inorganic compounds such as zirconyloxide-chloride and lead nitrate together with the abovenamed silicones;one of the purposes of the finishing treatment is, for instance,hydrophobing or rendering water repellent.

It is moreover known to use as hardening agents water-solubleaminoalkylsilanes, e.g. gamma-aminopropyltriethoxysilane.

The above-mentioned products have however a number of shortcomings whichdecrease the possibility of their use. Thus the metal salts oflong-chain carboxylic acids active as hardening agents are waterinsoluble, and it is thereforenecessary to convert them into stabledispersions miscible with water before they can be used in the finishingoperations. However, it is difficult to be sure that these dispersionswill be truly stable and it is not impossible that instable impregnatingliquors will thus result.

it is a further disadvantage that the use of metal salts as catalystsincurs a considerable decrease in resistance of the colors againstrubbing off. Therefore catalysts containing the above-described metalsalts cannot be used when the fibrous materials are supposed to have ahigh resistance to such rubbing offofcolors.

As to aminoalkylsilanes, these have a slightly alkaline reaction inwater; when using alkylor arylhydrogenpolysiloxanes as hydrophobingagents, hydrogen splitting will soon occur with decomposition of thealkyl(aryl)hydrogenpolysiloxane, and that renders impregnating liquorsuseless after a short time. Furthermore, aminoalkylsilanes are easilysubject to gelling. Up to the present, there are no agents known tocounteract the gelling.

It is the object of the present invention to provide a process whichwill permit to avoid the shortcomings of the methods hitherto known inthe improvement, particularly the hydrophobing treatment, of fibrousmaterials with the use of silicones.

it is a further object to provide a process for providing on textiles apermanent hydrophobing finish.

It is yet another object to provide a finishing process for fibrousmaterials in cases in which high resistance to rubbing off of colors isrequired.

Other objects and many of the attendant advantages will be readilyappreciated as the same becomes better understood by reference to thefollowing detailed description.

It has now been found that in the process of improving the properties offibrous materials, more particularly the finishing of textiles, theshortcomings caused by the presence of aminoalkylsilanes can beeliminated by using aminoalkylsilanes which have been treated withhydrofluoric acid. In the last-mentioned treatment, very stable additionproducts of aminoalkyltrifluorosilanes with hydrofluoric acid areobtained which proved to be very effective when added to known emulsionsof silicones as hardening catalysts. Even gelled aminoalkylsilanes anddistillation residues of aminoalkylsilanes can be used, which areotherwise not suitable for the preparation of such addition products.

The preparation of the addition products is not the subject matter ofthe present invention; they may be made in accordance with U.S. Pat.application Ser, No. 572,890 filed Aug. l7, I966 by Christian Dathe, oneof the coinventors of this application and others, and entitledProduction of Amino-Organofluorosilicates, issued as U.S. Pat. No.3,458,555 of July 29, 1969. The addition products are obtained ascrystalline, water-soluble products of the general formula NR (CH ),,SiF-mHF, in which R stands for hydrogen, an organic group or an organicamino group, e.g. -C,H,NH or -CH Cl-l NHCH Cl-l NH n=l to 8, preferably3 and 4, and m the number of N atoms in the molecule, but at least i.The compounds have considerable stability to water and they are used incombination with aqueous silicone emulsions for making fibrousmaterials, such as textiles, water repellent.

As already mentioned, the impregnating liquor prepared with siliconeemulsions and the addition products have extraordinary stability andlead to a hydrophobing finish which is laundry-proof and resistant tochemical cleaning, while allow ing the materials to maintain theircomplete resistance to rubbing off of colors.

The quantity of the addition product to be used as hardening acceleratoror catalyst, calculated on the silicone content of the emulsion, is notcritical. in general, 0.] to 50 parts by weight, preferably 1 to 30parts, of the addition product are used per parts by weight of silicone.The quantity is partly dependent on the type of fabric, its material,its weave, and the desired finishing effect. It is advantageous to makea preliminary test to determine the desirable amount of the additionproduct in each individual case.

The process according to the invention is especially suitable when thesilicone component consists of lower alkylhydrogenpolysiloxanes, e.g.methylhydrogenpolysiloxanes or mixtures of the same with lowerdialkylpolysiloxanes, e.g. dimethylpolysiloxanes.

The catalyst according to the invention also favorably affects thestability of the impregnating liquor in the presence of products forrendering the materials crease-proof, for instance in the presence ofurea-formaldehyde precondensates.

The invention will now be more fully explained in a number of examples,but it should be understood that these are given by way of illustrationand not of limitation and that many changes in the details can be madewithout departing from the spirit of the invention.

in the following all parts are given by weight, unless stated otherwise.

EXAMPLE 1 a. Preparation of the Silicone Emulsion To 50 parts of asolution consisting of 60 percent of a methylhydrogenpolysiloxane havinga viscosity of 16 est. (20 C.) and 40 percent of test benzine, we addsuccessively, while stirring, 1.5 parts of a nonylphenoxypolyglycolether and 48.5 parts of water; the so obtained preliminary emulsion ishomogenized in a homogenizer which permits adjustment to atm.superpressure.

b. Effecting the impregnation A mixed fabric consisting of 67 parts ofpolyester fiber and 35 parts of cotton is treated with an aqueousimpregnating liquor of the following composition: 30 g./l. of thesilicone emulsion as described in a. and 2.5 g./l. ofgamma-aminopropyltriflourosilane-hydrogenflouride, NH CH CH CH SiF 'HF,made according to the above-mentioned US. Pat. No. 3,458,555.

The impregnating liquor does not exhibit any splitting off of hydrogenupon use of polyhydrogensiloxanes and remains stable for a period of atleast 24 hours. lt imparts to the fabric the following properties:

treated not treated Spraying test according to "Spezilcx-Hydrophob" l 5Crease-restoring angle 1:60

according to TGL 0-53 830 l3l H15 Resistance to rubbing according to TGL0-54 02l 5 5 It should be added at this point, by way of explanation,that Spezitex is a collective trademark registered in the GermanDemocratic Republic, the use of which is limited by a strict adherenceto a number of tests set down in a circular dated June 1964.

Briefly stated, hydrophobing tests are carried out on a 20 cm. fiatpiece of textile specimen inclined at 45 to the horizontal plane, whichis sprayed with water from a height of 15 cm. The hydrophobing effect isindicated by the degree of adherence of the drops to the surface of thetextile, and is graded as follows:

1. Drops of water running off completely;

2. Slight adherence of drops on the sprayed surface;

3. Slight wetting of the sprayed surface;

4. Noticeable wetting of larger areas;

5. Complete soaking of the sprayed specimen.

TGL" stands for Technische Guete und Lieferbedingungen," anofficial/German-language/designation for accepted specifications of theGerman Democratic Republic, comparable to ASTM in U.S.A.

EXAMPLE 2 a. Preparation ofthe Silicone Emulsion In a high-speed stirrerType Ultra-Thurrax, made by the film Janke & Kunkel, Staufen, GermanFederal Republic:

17 parts dimethylpolysiloxane having a viscosity of 1000 cst. (20 0.),

13 parts methylhydrogenpolysiloxane having a viscosity of 50 cst.(20C.),

20 parts test benzine,

3 parts of a polyoxyethylene-sorbitane ester ofa fatty acid, and

47 parts water.

b. Effecting the lmpregnation A cotton fabric is finished by treating itwith an impregnating liquor of the following composition:

250 g./l. of an approx. 50 percent urea-formaldehyde precondensate, 4g./l. ammonium chloride,

2 g./l. glacial acetic acid,

50 g./l. the silicone emulsion prepared under a/ and g./l.gamma-diaminoethylenepropyltrifluorosilanehydrogenfluoride, NH CH CHNHCH CH CH SiF '2HF, made according to the U.S. Pat. No. 3,458,555.

The impregnating liquor, which remains effective for at least 8 hours,imparts to the cotton fabric the following highquality properties:

What we claim is:

1. In a process for improving fibrous materials, particularly forfinishing textiles, wherein an emulsion of a finishing agent is appliedto the textile substrate, the thus treated textile is then dried andfinally cured to obtain the finished article, the improvement comprisingimpregnating said fibrous materials with a liquor containing aqueousemulsions of alkylhydrogenpolysiloxanes or a mixture thereof withdialkylpolysiloxanes, in combination with a hardening catalystconsisting of an addition compound of an aminoalkylfluorosilane andhydrofluoric acid.

2. The process as defined in claim 1, wherein the ratio of siliconecontent in the emulsion and the hardening catalyst is parts by weightofsilicone: 0.1 to 50 parts of catalyst.

3. The process as defined in claim 2, wherein said ratio is 100 parts byweight of silicone: l to 30 parts of catalyst.

4. The process as defined in claim 1, wherein the silicone compound inthe emulsion is lower alkylhydrogenpolysiloxane and the addition productin the impre nating liquor is ammaaminopropyltrifluorosllane-hydrogenuoride of the ormula 5. The process as defined in claim 1, wherein thesilicone compound in the emulsion is methylhydrogenpolysiloxane and theaddition product in the impregnating liquor isgammaaminopropyltrifluorosilane-hydrogcnfluoride of the formula Nl-l CHCHB2CH SiF 'HF.

6. The process as defined in claim 1, wherein the silicone compound inthe emulsion is lower alkylhydrogenpolysiloxane in mixture with lowerdialkylpolysiloxane, the impregnating liquor also containing aurea-formaldehyde precondensate as crease-proofing agent, and theaddition product consists ofgamma-diaminoethylene-propyltrifluorosilane-bis-hydrogenfluoride of theformula NH CH CH NHCH CH CH SiF -ZHF.

7. The process as defined in claim 1, wherein the silicone compound inthe emulsion is methylhydrogenpolysiloxane in mixture withdimethylpolysiloxane, the impregnating liquor also containing anurea-formaldehyde precondensate as crease-proofing agent, and theaddition product consists ofgammadiaminoethylene-propyltrifluorosilane-bis-hydrogenfluoride of theformula NH CH CH NHCH CH Ch SiF '2l-l F.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,619,281 Dated November 9, 1971 Inirentofls) H. Kroning et a1.

It is certified that error appears in the above-identified patent andthat said Letters Patent are hereby corrected as shown below:

Claims 4 and 5, last lines (that is, column 4, lines 29 and 54 of thepatent) change to read NH CH CH CH Si]? Signed and sealed this 11th dayof April 1972.

(SEAL) Attest:

EDWARD M.FLETCHEE,JR. ROBERT GOTTSCHALK Attesting Officer Commissionerof Patents )RM Po-1050 (10-69) uscoMM-Dc 60376-P69 U75. GOVERNMENTPRINTING OFFICE 1 I969 O355'3J4

2. The process as defined in claim 1, wherein the ratio of siliconecontent in the emulsion and the hardening catalyst is 100 parts byweight of silicone: 0.1 to 50 parts of catalyst.
 3. The process asdefined in claim 2, wherein said ratio is 100 parts by weight ofsilicone: 1 to 30 parts of catalyst.
 4. The process as defined in claim1, wherein the silicone compound in the emulsion is loweralkylhydrogenpolysiloxane and the addition product in the impregnatingliquor is gamma-aminopropyltrifluorosilane-hydrogenfluoride of theformula NH2CH2CH2CH2SiF3.HF.
 5. The process as defined in claim 1,wherein the silicone compound in the emulsion ismethylhydrogenpolysiloxane and the addition product in the impregnatingliquor is gamma-aminopropyltrifluorosilane-hydrogenfluoride of theformula NH2CH2CH2CH2SiF3.HF.
 6. The process as defined in claim 1,wherein the silicone compound in the emulsion is loweralkylhydrogenpolysiloxane in mixture with lower dialkylpolysiloxane, theimpregnating liquor also containing a urea-formaldehyde precondensate ascrease-proofing agent, and the addition product consists ofgamma-diaminoethylene-propyltrifluorosilane-bis-hydrogenfluoride of theformula NH2CH2CH2NHCH2CH2CH2SiF3.2HF.
 7. The process as defined in claim1, wherein the silicone compound in the emulsion ismethylhydrogenpolysiloxane in mixture with dimethylpolysiloxane, theimpregnating liquor also containing an urea-formaldehyde precondensateas crease-proofing agent, and the addition product consists ofgamma-diaminoethylene-propyltrifluorosilane-bis-hydrogenfluoride of theformula NH2CH2CH2NHCH2CH2Ch2SiF3.2HF.